qlge: Fix TX queue stoppage due to full condition.

TX queue was being stopped at beginning of send path instead
of at the end when last descriptor is used.

Signed-off-by: Jitendra Kalsaria <jitendra.kalsaria@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 11 insertions, 1 deletions

diff --git a/drivers/net/ethernet/qlogic/qlge/qlge_main.c b/drivers/net/ethernet/qlogic/qlge/qlge_main.c
index ca427eb32369..fb86f06e8f1e 100644
--- a/drivers/net/ethernet/qlogic/qlge/qlge_main.c
+++ b/drivers/net/ethernet/qlogic/qlge/qlge_main.c
@@ -2556,7 +2556,7 @@ static netdev_tx_t qlge_send(struct sk_buff *skb, struct net_device *ndev)
 
         if (unlikely(atomic_read(&tx_ring->tx_count) < 2)) {
                 netif_info(qdev, tx_queued, qdev->ndev,
-                           "%s: shutting down tx queue %d du to lack of resources.\n",
+                           "%s: BUG! shutting down tx queue %d due to lack of resources.\n",
                            __func__, tx_ring_idx);
                 netif_stop_subqueue(ndev, tx_ring->wq_id);
                 atomic_inc(&tx_ring->queue_stopped);
@@ -2610,6 +2610,16 @@ static netdev_tx_t qlge_send(struct sk_buff *skb, struct net_device *ndev)
                      tx_ring->prod_idx, skb->len);
 
         atomic_dec(&tx_ring->tx_count);
+
+        if (unlikely(atomic_read(&tx_ring->tx_count) < 2)) {
+                netif_stop_subqueue(ndev, tx_ring->wq_id);
+                if ((atomic_read(&tx_ring->tx_count) > (tx_ring->wq_len / 4)))
+                        /*
+                         * The queue got stopped because the tx_ring was full.
+                         * Wake it up, because it's now at least 25% empty.
+                         */
+                        netif_wake_subqueue(qdev->ndev, tx_ring->wq_id);
+        }
         return NETDEV_TX_OK;
 }